Field of the Invention
The present invention relates to nanostructured materials (including nanowires) for use in batteries. Exemplary materials include carbon-comprising, Si-based nanostructures, nanostructured materials disposed on carbon-based substrates, and nanostructures comprising nanoscale scaffolds. The present invention also provides methods of preparing battery electrodes, and batteries, using the nanostructured materials.
Background of the Invention
Traditional batteries, including lithium (Li) ion batteries, comprise an anode, a separator material with an electrolyte medium, and a cathode. The anode electrode of most commercially available Li ion batteries is a copper foil coated with a mixture of graphite powder and a polymer blend such as polyvinylidene difluoride (PVDF). The cathode generally comprises a mixture of lithium transition metal oxides, PVDF and carbon black coated onto an aluminum foil. While graphite and LiCoO2 are normally used, and have high coulombic efficiencies, there is a need for improved anode materials with superior storage capacity and thermal stability.
One material that has attracted a great deal of attention is silicon (Si), due to its high capacity. However, repeated charging/discharging cycles have been found to cause a volume change in the Si, which can ultimately cause the material to disintegrate and severely limit any potential battery life. Thus, there is a need for improved electrode materials for use in batteries, and specifically, Si-based materials.